77638788864 has 648 divisors, whose sum is σ = 287554743840. Its totient is φ = 19595132928.

The previous prime is 77638788833. The next prime is 77638788883. The reversal of 77638788864 is 46888783677.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 77638788792 and 77638788801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 687068872 + ... + 687068984.

Almost surely, 2^77638788864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77638788864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143777371920).

77638788864 is an abundant number, since it is smaller than the sum of its proper divisors (209915954976).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77638788864 is a wasteful number, since it uses less digits than its factorization.

77638788864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297 (or 167 counting only the distinct ones).

The product of its digits is 606928896, while the sum is 72.

The spelling of 77638788864 in words is "seventy-seven billion, six hundred thirty-eight million, seven hundred eighty-eight thousand, eight hundred sixty-four".